Alaric Watts in his 'Biographical Sketch of J. M. W. Turner' records details of his early association with Girtin beginning with the highly dubious claim that they worked together in the studio of John Raphael Smith (1752 - 1812) (Watts, 1857, pp.xi–xii).
Here he formed an intimacy with Girtin, the founder of the English School of Water-Colour Painting, who was engaged like himself to colour prints in Mr. Smith's establishment. There can be no doubt that Turner's acquaintance with that clever and truthful water-colour painter exercised a most beneficial influence on his pencil. The style of young Girtin exhibited a manifest improvement on the hard and bald accuracy of Paul Sandby and his followers, and had he lived, he might have proved a formidable rival to his friend, whose senior he was by about two years. Unhappily, however, for the interests of art, he died in 1802, not, as has been represented, from an illness engendered by dissipated habits, but of an asthmatical complaint, which had its origin in a cold caught whilst sketching. His son, Mr. Calvert Girtin, describes his father and young Turner as associated in a friendly rivalry under the hospitable roof and superintendence of that lover of art, Dr. Monro, (then residing in the Adelphi.) Nor was Turner forgetful of the Doctor's kindness, for in referring to that period of his career, in a conversation with Mr. David Roberts, he said, "there," pointing to Harrow, "Girtin and I have often walked to Bushy and back to make drawings for good Dr. Monro at half-a-crown a piece and a supper." Girtin had received the benefit of a more regular education than Turner, having been a pupil of Dayes, and a student of the Royal Academy for nearly three years. He had also the advantage of having accompanied one of his early patrons in repeated tours among the most picturesque scenery of England, Scotland, and Wales, at a time when Turner's means afforded him no opportunity of sketching from nature beyond the outskirts of the metropolis. Girtin was the first who introduced the custom of drawing upon cartridge paper, thus avoiding the glare common to a smooth white surface. Many of Turner's early drawings were made on paper of this description; and some of the finest of his later designs, although of magical effect, were executed on coarse blue paper. If imitation be indeed, as we are assured it is, the sincerest flattery, there can be little doubt of the very high opinion entertained of Girtin by Turner, for we have seen one of his drawings of this time that might almost be mistaken for the work of his friend. Girtin's breadth of handling and knowledge of light and shade, and his acquaintance with aerial perspective, would seem not to have been lost on Turner. Had his friendly rival lived, they might have assisted each other. Their joint work of English River Scenery, engraved by Chas. Turner, and published in 1825-6 by W. B. Cooke, is a production of high art, worthy to be a companion to the Liber Studiorum. Turner's earliest knowledge of perspective has been ascribed to his study of 'Malton's Treatise,' but it seems more likely that a new occupation which he entered upon, about this time, that of supplying skies and foregrounds to the architectural drawings of Porden, an architect then in great practice, afforded him facilities for acquiring a more perfect knowledge of this branch of his art.
M. I. H. (John Hornby Maw), ‘The Use of Indigo. Turner’s Drawings’, The Builder, vol.15, no.768 (24 October 1857), p.609
John Hornby Maw (1800–85), writing as ‘M. I. H.’, was the first to describe the deleterious effect of Girtin’s use of the fugitive indigo pigment and, more particularly, in the early watercolours of Joseph Mallord William Turner (1775–1851). Maw describes the effect of light on Turner’s Powis Castle (Manchester Art Gallery (1917.117)), but he might have equally been talking about one of the three watercolours by Girtin that he owned, the badly faded A Rainbow over the River Exe (TG1730).
In the days before cobalt and French blues were invented, water-colour painters had scarcely any alternative between indigo and Prussian blue. The use of indigo was, however, the rule, and that of the prussiate of iron the exception, because no pigment is so capable as indigo of representing aërial tints and tones, or so available in the formation of landscape greens and greys in every variety of tenderness or intensity.
This otherwise valuable pigment has, however, one fault of such magnitude as ought totally to exclude it from a place in the matériel of the conscientious artist. It is one of the most evanescent of pigments. I speak, of course, of the indigo of commerce, simply ground and made up for use as a water-colour … It is now some twelve years ago that an ardent admirer and collector of Turner’s water-colour works, on taking one of the England and Wales drawings out of the frame in which it had been exposed to the action of light for only a few months, was struck by the novel appearance of a clearly defined marginal band of colour, “fresher” or bluer than the rest, and extending all round the drawing. The fact was, the drawing had been put into a frame somewhat too small for it, and consequently a portion of the colouring had been covered by the "rebate,” and thereby protected from the bleaching power of light from which the rest of the drawing had evidently suffered. It was, however, equally evident that the component pigments had faded unequally, from the fact that the faded portion had become decidedly redder than the portion protected by the rebate. The pure bright yellows had gone but little, though perceptibly. The madder lake, as well as the ferruginous reds, remained in all their original power. The proprietor of the drawing to which I have referred decided at once upon what was afterwards proved to be the real cause of mischief, and was thereby enabled to understand how it was that he had so often been perplexed, in revisiting various collections of Turner drawings, by fresh discoveries of red clouds, &c. where he thought he used to see grey ones. An appeal was, however, made to Turner himself, who requested to see the drawing which it was alleged had faded. It was shown to him at his house in Queen Anne-street, in the presence of a gentleman well known to almost every collector of Turner drawings. On taking it into his hand Turner exclaimed, “I will never make another water-colour drawing,”–a resolution which he did not very long maintain. On being asked if he would have the kindness to blend the faded and unfaded portions of the damaged drawing a little, the answer was equally decided and characteristic. “Oh no! if I were to do that I should have all my drawings brought to be restored.” He admitted that he still adhered to the use of indigo, having supposed it to be a permanent material. On asking him whether he had not observed that all his early drawings, and those of Girtin, which had been long exposed to light, had become rusty, or what is called foxy, in colour, he made no answer, but said, “Well, what am I to use for greys?” The reply was, cobalt. I do not suppose that Turner used indigo from that time. By far the greater part of his drawings have been, however, made with this very fugitive pigment.
A Rainbow over the River Exe